Son of Sardar in School

Bantu returns from his first day at school and immediately questions his
father." Dad, today we had a Spelling Class - All the other kids could
only say half the alphabet, but I knew the whole thing. Is that because
I am Sardar?"
"No son, that's because you are intelligent. "
Bantu seeming content with the answer, asks his
father another question, "Dad, today we had Math class - All the other
kids could only count from 1-10, I could count from 1 to 20. Is this
because I am Sardar ??"
"No son, that's because you are intelligent," replies his father.
Happy with the answer, Bantu poses another question to his father, "Dad,
today we had Medical Examination, all the other boys were shorter than me,
I was atleast twice their height. Is that because I am Sardar ??"
The father replies, "No son, that's because you are 31 years old."